<PRE><B>Question 461309</B>
*[tex \LARGE A = \frac{1}{2}h(b_1 + b_2)]


*[tex \LARGE 84 = \frac{1}{2}h(9 + 15) = 12h]


*[tex \LARGE h = 7 ft]


You just have to know how to apply the formula, not just bluntly apply it by doing something like *[tex A = \frac{1}{2}(84)(9 + 15)].</PRE>